Looks like a serious competitor to Unity. Modern C# is really easy to pick up for beginners (that's actually how I started learning programming back around 2010).
What does monetization look like? Can you ship standalone games? Source 2 licensing requirements? Is this closer to Unity or closer to Roblox when it comes to publishing?
You can't ship standalone games yet, they're currently in talks with Valve, lawyers talking to lawyers to try and make this happen. Right now, they have a Play Fund, and pay creators for minutes played, similar to Fortnite. This is definitely closer to Roblox for now, but yeah standalone coming soon hopefully..
A major advantage of using modern game engines is the multiplatform support. This seems pretty weak on that front.